The Most Endangered Marine Mammal Still Exists. Here’s the Latest Count.

During a few weeks each year or so, an international team of scientists spends long days at sea searching for the most endangered marine mammal on Earth: the vaquita porpoise. The species is teetering on the edge of extinction, with recent surveys estimating around 10 individuals in the area where they’ve been considered most likely to live.

Results from this year’s survey, issued on Tuesday, were disappointing: Researchers estimate they saw six to eight individual vaquitas there, the lowest result ever recorded.

Still, the scientific team and the Mexican government cautioned that the population had not necessarily declined, emphasizing that more vaquitas may exist outside the search area. Since at least 2019, the visual surveys have focused on one zone where acoustic monitoring and other research has suggested the remaining animals congregate.

“It’s worrisome,” said Barbara Taylor, a longtime vaquita researcher who led the survey. “We just need to go out and find out whether the vaquitas have moved someplace else and adapt the management accordingly.”

The world’s smallest porpoise, vaquitas have rounded faces with panda-like markings around their eyes and lips that seem to pull up into a Mona Lisa smile. Their name in Spanish, vaquita marina, means little sea cow.

The individuals observed during the survey appeared in good health. One group of four included a yearling.